Let's not enable the 4:4:4->4:2:0 conversion bit in the DFP unless we're
actually outputting YCbCr 4:4:4. It would appear some protocol
converters blindy consult this bit even when the source is outputting
RGB, resulting in a visual mess.
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2914
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210111164111.13302-1-ville.syrjala@linux.intel.com
Fixes:
181567aa9f0d ("drm/i915: Do YCbCr 444->420 conversion via DP protocol converters")
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
drm_dbg_kms(&i915->drm, "Failed to set protocol converter HDMI mode to %s\n",
enableddisabled(intel_dp->has_hdmi_sink));
- tmp = intel_dp->dfp.ycbcr_444_to_420 ?
- DP_CONVERSION_TO_YCBCR420_ENABLE : 0;
+ tmp = crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR444 &&
+ intel_dp->dfp.ycbcr_444_to_420 ? DP_CONVERSION_TO_YCBCR420_ENABLE : 0;
if (drm_dp_dpcd_writeb(&intel_dp->aux,
DP_PROTOCOL_CONVERTER_CONTROL_1, tmp) != 1)